1. Field of the Invention
The present invention is directed to the field of digital rights management. More specifically, the present invention is directed to digital watermarking processes and systems.
2. Description of the Related Art
In the field of documents and publishing, a work created by an author is usually provided to a publisher which formats, duplicates and/or prints numerous copies of the document. A “document”, as the term is used herein, is any unit of information subject to distribution or transfer, including but not limited to correspondence, books, magazines, journals, newspapers, other papers, software, photographs and other images, audio and video clips, and other multimedia presentations or products. A document may be embodied in printed form on paper, as digital data on a storage medium, or in any other known manner on a variety of media. The copies of the document are then sent by a distributor to bookstores or other retail outlets, from which the copies are purchased by end users. With the advent of current computing and communications systems such as personal computers, workstations, and other devices connected over communications networks such as local area networks (LANs), intranets, and the Internet, publishers and authors are increasingly publishing their documents electronically to minimize cost and delays. Presently, audio and video recordings, software, books, journals and multimedia works, are all being electronically published.
A fundamental issue facing the publishing and other information industries as they consider electronic publishing, is how to prevent the unauthorized and unaccounted distribution or usage of electronically published documents. Electronically published documents are typically distributed in digital form and recreated in a computer based system having the capability to recreate the published document. The ease in which electronically published documents can be accurately reproduced and distributed is a major concern. Because publisher, authors, as well as other parties in these industries receive royalties for each published document that is delivered (i.e. sold), any unaccounted distribution of the document such as by copying or distribution to another digital medium results in unpaid royalties. Moreover, whereas the low quality of copying and the high cost of distributing printed material have served as deterrents to unauthorized copying in the past, it is far too easy to copy, modify, and redistribute unprotected digital documents. Accordingly, some method some method of protecting digital documents is necessary to make it more difficult to copy such documents without authorization. Efforts to resolve this problem have been termed “Intellectual Property Rights Management” (“IPRM”), “Digital Property Rights Management” (“DPRM”), “Intellectual Property Management” (“IPM”), “Rights Management” (“RM”), and “Electronic Copyright Management” (“ECM”), collectively referred to as “Digital rights management (DRM)” herein. There are a number of issues in digital rights management: authentication, authorization, accounting, payment and financial clearing, rights specification, rights verification, rights enforcement, and document protection, for example.
Two basic schemes have been employed to attempt to solve the document protection problem. The first approach is the use of subscription based services in which the user is granted access to the document (or information to generate the document) only after paying a subscription fee. Existing digital rights management systems such as IBM's Cryptolopes utilizes encryption technology to encrypt documents which are then decrypted by users who have paid for the documents or have been otherwise authorized to have access to the documents. However, once these documents are distributed and have been decrypted by an end user system, little protection is available to prevent copying or distributing the decrypted document. In addition, there is no effective way to trace back such copies of the document to the original source and the intended user. The second approach is to utilize proprietary formats wherein the document can only be generated by a select application that is obligated to enforce the publisher's rights. Of course, this approach requires the use of a single proprietary format and thus, one loses the ability to combine popular formats and the richness of content associated therewith. In addition, this approach requires the user to use a previously unknown application and requires development of the select application in order for each format to be created in a secure manner. Furthermore, the documents must be generated or converted using non-standard tools.
To deter “pirating”, i.e. unauthorized copying, use, or distribution of the documents, “watermarks” are frequently used to identify the copyright owners, authorized users, and/or distributors. Such watermarking also aids in the identification of the source of the document thereby allowing enforcement of the rights of the publisher and/or the author. With respect to the digitally published documents, current digital watermarking technology digitally marks the document with details such as information provided by the copyright owner, the authorized user, or the distributor. Typically, a watermark is used to identify the source or originator of a document. If the watermark is used to identify the user to whom the document is delivered, it is typically referred to as a “fingerprint”. The technologies utilized for both watermarking, and fingerprinting, are typically the same. Thus, the term “watermarking” is used herein to refer to both watermarking and fingerprinting, and the terms “watermark” and “mark” are also used herein to refer to both watermarks and fingerprints.
Presently, most existing watermarking products or tool kits generate marked documents via document editors or special tools. For instance, Adobe Photo Shop® is a widely used software tool for image creation and publishing on the Internet. DigiMarc Corporation has provided a plug-in to Photo Shop 4.0® which allows a user to embed into an image, a digital ID (which is issued by DigiMarc) as well as some attributes such as the type of use and content. IBM® has also introduced digital watermarking technology through a plug-in for Photo Shop® to identify and preserve the rights of digital content owners. In addition, watermarking of audio clips such as a music file has also been attained by converting the music file into a frequency domain utilizing Fourier transforms, embedding a watermarking signal at a desired frequency range, and reconverting the music file. In this regard, efforts have been taken to standardize DRM of digital music as evidenced by the Secure Digital Music Initiative which may be found in the Internet address www.sdmi.org.
Despite the utility that the above-described plug-ins and watermarking techniques provide, these watermarking products have several key limitations. More specifically, the present applicants have found that the current processes and systems “bind” or affix the content information into the watermark at early stages of the document life cycle thereby limiting the type of content information which can be stored in the watermark to “static” information which is known or already determined. Another limitation arise from the fact that watermarks are frequently placed into documents manually through the use of WYSIWYG (what you see is what you get) editors or other tools. Tools exist for merging watermarks into multiple same objects (such as images) of a target document automatically. However, such tools do not facilitate insertion of various watermarks into target documents that have multiple differing objects. Moreover, the use of existing processes and systems for inserting watermarks are limited to a single watermarking technology and thus, are limited to utilizing one predetermined application. Consequently, the existing systems and methods do not allow selection of different or multiple technologies nor support use of such different technologies.
Therefore, there exists an unfulfilled need for a watermarking process and system which will provide a solution to the above noted limitations to thereby allow efficient creation and use of watermarks to identify and preserve the rights of digital content owners.